/*
 * TeleStax, Open Source Cloud Communications  Copyright 2012.
 * and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.mobicents.protocols.ss7.map.service.mobility.authentication;

import java.io.IOException;
import org.mobicents.protocols.asn.AsnException;
import org.mobicents.protocols.asn.AsnInputStream;
import org.mobicents.protocols.asn.AsnOutputStream;
import org.mobicents.protocols.asn.Tag;
import org.mobicents.protocols.ss7.map.api.MAPException;
import org.mobicents.protocols.ss7.map.api.MAPParsingComponentException;
import org.mobicents.protocols.ss7.map.api.MAPParsingComponentExceptionReason;
import org.mobicents.protocols.ss7.map.api.service.mobility.authentication.AuthenticationTriplet;
import org.mobicents.protocols.ss7.map.primitives.MAPAsnPrimitive;

/**
 * 
 * @author sergey vetyutnev
 * 
 */
public class AuthenticationTripletImpl implements AuthenticationTriplet, MAPAsnPrimitive {

	public static final String _PrimitiveName = "AuthenticationTriplet";

	private byte[] rand;
	private byte[] sres;
	private byte[] kc;

	
	public AuthenticationTripletImpl() {
	}

	public AuthenticationTripletImpl(byte[] rand, byte[] sres, byte[] kc) {
		this.rand = rand;
		this.sres = sres;
		this.kc = kc;
	}	


	public byte[] getRand() {
		return rand;
	}

	public byte[] getSres() {
		return sres;
	}

	public byte[] getKc() {
		return kc;
	}

	public int getTag() throws MAPException {
		return Tag.SEQUENCE;
	}

	public int getTagClass() {
		return Tag.CLASS_UNIVERSAL;
	}

	public boolean getIsPrimitive() {
		return false;
	}


	public void decodeAll(AsnInputStream ansIS) throws MAPParsingComponentException {

		try {
			int length = ansIS.readLength();
			this._decode(ansIS, length);
		} catch (IOException e) {
			throw new MAPParsingComponentException("IOException when decoding " + _PrimitiveName + ": " + e.getMessage(), e,
					MAPParsingComponentExceptionReason.MistypedParameter);
		} catch (AsnException e) {
			throw new MAPParsingComponentException("AsnException when decoding " + _PrimitiveName + ": " + e.getMessage(), e,
					MAPParsingComponentExceptionReason.MistypedParameter);
		}
	}

	public void decodeData(AsnInputStream ansIS, int length) throws MAPParsingComponentException {

		try {
			this._decode(ansIS, length);
		} catch (IOException e) {
			throw new MAPParsingComponentException("IOException when decoding " + _PrimitiveName + ": " + e.getMessage(), e,
					MAPParsingComponentExceptionReason.MistypedParameter);
		} catch (AsnException e) {
			throw new MAPParsingComponentException("AsnException when decoding " + _PrimitiveName + ": " + e.getMessage(), e,
					MAPParsingComponentExceptionReason.MistypedParameter);
		}
	}

	private void _decode(AsnInputStream ansIS, int length) throws MAPParsingComponentException, IOException, AsnException {

		this.rand = null;
		this.sres = null;
		this.kc = null;

		AsnInputStream ais = ansIS.readSequenceStreamData(length);
		int num = 0;
		while (true) {
			if (ais.available() == 0)
				break;

			int tag = ais.readTag();

			switch (num) {
			case 0:
				// rand
				if (ais.getTagClass() != Tag.CLASS_UNIVERSAL || !ais.isTagPrimitive() || tag != Tag.STRING_OCTET)
					throw new MAPParsingComponentException(
							"Error while decoding " + _PrimitiveName + ".rand: Parameter 0 bad tag or tag class or is not primitive",
							MAPParsingComponentExceptionReason.MistypedParameter);
				this.rand = ais.readOctetString();
				if (this.rand.length != 16)
					throw new MAPParsingComponentException("Error while decoding " + _PrimitiveName + ".rand: Bad field length: 16 is needed, found: "
							+ this.rand.length, MAPParsingComponentExceptionReason.MistypedParameter);
				break;

			case 1:
				// sres
				if (ais.getTagClass() != Tag.CLASS_UNIVERSAL || !ais.isTagPrimitive() || tag != Tag.STRING_OCTET)
					throw new MAPParsingComponentException(
							"Error while decoding " + _PrimitiveName + ".sres: Parameter 1 bad tag or tag class or is not primitive",
							MAPParsingComponentExceptionReason.MistypedParameter);
				this.sres = ais.readOctetString();
				if (this.sres.length != 4)
					throw new MAPParsingComponentException("Error while decoding " + _PrimitiveName + ".sres: Bad field length: 4 is needed, found: "
							+ this.sres.length, MAPParsingComponentExceptionReason.MistypedParameter);
				break;

			case 2:
				// kc
				if (ais.getTagClass() != Tag.CLASS_UNIVERSAL || !ais.isTagPrimitive() || tag != Tag.STRING_OCTET)
					throw new MAPParsingComponentException(
							"Error while decoding " + _PrimitiveName + ".kc: Parameter 2 bad tag or tag class or is not primitive",
							MAPParsingComponentExceptionReason.MistypedParameter);
				this.kc = ais.readOctetString();
				if (this.kc.length != 8)
					throw new MAPParsingComponentException("Error while decoding " + _PrimitiveName + ".kc: Bad field length: 8 is needed, found: "
							+ this.kc.length, MAPParsingComponentExceptionReason.MistypedParameter);
				break;
			}

			num++;
		}

		if (num < 3)
			throw new MAPParsingComponentException("Error while decoding " + _PrimitiveName + ": Needs at least 3 mandatory parameters, found "
					+ num, MAPParsingComponentExceptionReason.MistypedParameter);
	}

	public void encodeAll(AsnOutputStream asnOs) throws MAPException {

		this.encodeAll(asnOs, this.getTagClass(), this.getTag());
	}

	public void encodeAll(AsnOutputStream asnOs, int tagClass, int tag) throws MAPException {
		
		try {
			asnOs.writeTag(tagClass, this.getIsPrimitive(), tag);
			int pos = asnOs.StartContentDefiniteLength();
			this.encodeData(asnOs);
			asnOs.FinalizeContent(pos);
		} catch (AsnException e) {
			throw new MAPException("AsnException when encoding " + _PrimitiveName + ": " + e.getMessage(), e);
		}
	}

	public void encodeData(AsnOutputStream asnOs) throws MAPException {

		if (this.rand == null || this.sres == null || this.kc == null) {
			throw new MAPException("rand, sres and kc fields must not be null");
		}
		if (this.rand.length != 16)
			throw new MAPException("Wrong rand field length: must be 16, found " + this.rand.length);
		if (this.sres.length != 4)
			throw new MAPException("Wrong sres field length: must be 4, found " + this.rand.length);
		if (this.kc.length != 8)
			throw new MAPException("Wrong kc field length: must be 8, found " + this.rand.length);
		
		try {
			asnOs.writeOctetString(this.rand);
			asnOs.writeOctetString(this.sres);
			asnOs.writeOctetString(this.kc);
		} catch (IOException e) {
			throw new MAPException("IOException when encoding " + _PrimitiveName + ": " + e.getMessage(), e);
		} catch (AsnException e) {
			throw new MAPException("AsnException when encoding " + _PrimitiveName + ": " + e.getMessage(), e);
		}
	}

	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();
		sb.append("AuthenticationTriplet [");

		if (this.rand != null) {
			sb.append("rand=[");
			sb.append(printDataArr(this.rand));
			sb.append("], ");
		}
		if (this.sres != null) {
			sb.append("sres=[");
			sb.append(printDataArr(this.sres));
			sb.append("], ");
		}
		if (this.kc != null) {
			sb.append("kc=[");
			sb.append(printDataArr(this.kc));
			sb.append("]");
		}

		sb.append("]");

		return sb.toString();
	}

	private String printDataArr(byte[] arr) {
		StringBuilder sb = new StringBuilder();
		for (int b : arr) {
			sb.append(b);
			sb.append(", ");
		}

		return sb.toString();
	}
}

